Difference between 83-86 EFI and 87-97 gas tanks?

[ForeverDrivin]

Hey all, coming in to see if anyone has some esoteric knowledge about the difference between the EFI gas tanks.

General online consensus (LMR, Ebay, some forms) is that all EFI tanks from 83-97 are the same, so many gas tanks out there rated for all 83-97 cars. Even LMRs little diagram says 15.4 gal for all Fox + SN cars.

I picked up a foxbody tank for my SN and swapped out the fuel level sender for an SN sender, and I find out that the swing on the arms is physically different? The SN sender is reading half full on a completely dry tank. Take it out and see the sender sits lower than the foxbody sender at its lowest. Considering the sender that came out, I think the tank was for a 83-86.

I ended up bending the SN sender just to match the "low" reading, but a bit pissed that it'll never read full.

I also noticed that the fuel filler neck holes seem to be slightly different sizes... I couldn't really get my newer grommet into the hole on this old tank.

All EFI tanks are 15.4 gallons, right? Even if the way the sender sits is different or the fuel neck has a different hole size?

Any help appreciated!

 

[Mustang5L5]

Can you post photos? The fuel filter grommet is the same from 1982-1997, so it not fitting is a big clue here.

Do you see any engineering numbers on the old sender, or any of the parts on the tank? That might be a clue as to what year it is from

 

[ForeverDrivin]

While I have no direct photos of the tank, I can show you a photo I took of the baffling inside. I can also show you pictures of the level sender that came out, the only product # on there, and the new vs old neck grommet plus the old grommets part #. The old grommet # seems to point towards both 83-97 grommets and 69-71 grommets. Strange. The old grommet has a larger hole and its "sealing radius" is larger than my old one, with a smaller center hole and a seemingly smaller sealing radius.

Perhaps I will just try shoving my new grommet in there again, it could be possible they did the same with this fatter grommet. It is 100% an EFI tank, and looks exactly like my old tank, so I'm not sure what other cars this EFI tank could even be in prior to 1982.

 

[ForeverDrivin]

While I have no direct photos of the tank, I can show you a photo I took of the baffling inside. I can also show you pictures of the level sender that came out, the only product # on there, and the new vs old neck grommet plus the old grommets part #. The old grommet # seems to point towards both 83-97 grommets and 69-71 grommets. Strange. The old grommet has a larger hole and its "sealing radius" is larger than my old one, with a smaller center hole and a seemingly smaller sealing radius.

Perhaps I will just try shoving my new grommet in there again, it could be possible they did the same with this fatter grommet. It is 100% an EFI tank, and looks exactly like my old tank, so I'm not sure what other cars this EFI tank could even be in prior to 1982.

Forgot this image of the baffle. Even if I took the tank out, I likely already painted over any part numbers unfortunately.

 

[Mustang5L5]

Well the part number E2DC-9072-AA is a clue. That's a 1982 engineering part number. D is Ford "car-line" so it likely pointed to a Fox-chassis passenger car.

The part number on the fuel tank sender is an aftermarket part number. I recognize the format, so it's likely one of the major brands. What is the resistance of the sender? They have different resistance values based on applications.

Searching online, it appears the part number for a 79-81 tank is E1AZ-9072. I can't find the early part number for the late 81 grommet as any search pulls up the revised 1994 F4ZZ-9072 part number.

My guess is the tank came out of a 1982+ Fox chassis non-mustang vehicle. Where did you buy it from? I wouldn't be surprised if someone sold it as a Mustang tank as a lot of these parts folk tend to think "are all the same"

 

[ForeverDrivin]

Well the part number E2DC-9072-AA is a clue. That's a 1982 engineering part number. D is Ford "car-line" so it likely pointed to a Fox-chassis passenger car.

The part number on the fuel tank sender is an aftermarket part number. I recognize the format, so it's likely one of the major brands. What is the resistance of the sender? They have different resistance values based on applications.

Searching online, it appears the part number for a 79-81 tank is E1AZ-9072. I can't find the early part number for the late 81 grommet as any search pulls up the revised 1994 F4ZZ-9072 part number.

My guess is the tank came out of a 1982+ Fox chassis non-mustang vehicle. Where did you buy it from? I wouldn't be surprised if someone sold it as a Mustang tank as a lot of these parts folk tend to think "are all the same"

I've been going through some Ford part # decoders and it seems the most consistent answer I can find is 1982 Falcon/Maverick/Taurus.

Unfortunate! You are right to say most just assume they are fox tanks, just like me and the seller did. Frankly I bought it off some guy with a New Edge who no longer needed it after he found a fuel cell.

I suppose I will order a grommet and see if I cant shove my filler neck into it, and if not I will have to find a new tank.

What an interesting answer! I never even thought to decode the part number. Thanks for the help.